Plot a pixel intensity image

Hi I would like to plot a pixel image like figure with a color range red,yellow, green,blue. In example I couldnt find red as a combination.

Attached images for example.

Answer 1

[Matt J]

Perhaps with 'jet',

imshow('cameraman.tif')
colormap jet
colorbar

[Muniyat Rafa]

Thank you so much Matt J I could bring the color range :D

Now for drawing how can I draw an image which is round in structure whereas pixel box is square in structure. Shall I increase the number of matrix?

[Matt J]

Thank you so much Matt J I could bring the color range :D

You're very welcome. Please Accept-click the answer to cofirm that it reoslved your question.